Bearings mounted on a wheel spindle of a vehicle generally are retained by a spindle nut. The nut is threadably installed on the end of the spindle to engage a race of a bearing. The nut is torqued to positively retain the bearings and to also establish a pre-load on the bearings. The nut must be secured in its torqued position so that the nut will not become loosened or in the rare instance be tightened further. The nut is secured in its torqued position to maintain the pre-load on the bearings and also for safety reasons. The nut once tightened to the desired pre-load is prevented from rotating relative to the spindle by a locking or retention device.
Wheel spindles such as those utilized for four wheel drive vehicles, front wheel drive vehicles and similar applications require a locking device that does not protrude through the center of the wheel spindle. The locking device therefore must be mountable on the periphery of the wheel spindle and be arranged to secure the spindle nut in a set position.
Typically the wheel spindle has a key way in its threaded portion that is utilized by the locking device to prevent rotation of the spindle nut. Various forms of spindle locking devices have been utilized in the past. One example considered most similar to the present invention is an elongated keying pin. The spindle nut is provided with multiple axially directed grooves symmetrically positioned in its threaded periphery. When the desired torque is achieved, the nut is adjusted to align or superimpose the closest of the multiple grooves with the spindle key way. The keying pin is inserted into the aligned groove and key way to prevent further rotation of the spindle nut. This keying pin accomplishes the desired locking of the spindle nut. However, the keying pin is difficult to handle and difficult to detect as it becomes buried between the spindle and nut. Detection is important for inspection purposes and handling difficulties impede assembly. Furthermore, the buried keying pin can be difficult to remove when disassembly is necessary, e.g., for maintenance purposes.